Firing with cremation remains is very similar to firing
with any organic material encapsulated into glass.
Design
There are several possible design approaches.
Drilling holes is one method to avoid bubbles. You can drill the base, put the remains on
top and then cap. Place the whole
assembly on 1mm fibre paper to allow the air to migrate out through the hole
and fibre paper under the glass.
Alternatively, you fire upside down and then fire
polish the top. Place the eventual top down onto
the kiln washed shelf or Thinfire. Place the remains on the glass and cap with
the glass that has the hole drilled.
Fire, then clean, turn over and fire polish the final top surface.
Design the piece and placing so there is a gap at the edge.
This gives a route for air to escape. If there is any gap left after fusing, it can
be filled with a bit of super glue or other clear glue.
Another method is to place pieces of frit or stringer at
the very edge of the base glass to allow air out from under the centre of the
piece.
If you do not need to concentrate the cremains in one
area, you can disperse the material evenly across the piece to reduce the
possibility of large bubbles. The air
and gasses can migrate to the edge through the particles, just as happens with
powder sprinkled between layers of glass.
You can combine some of these methods as they are not
mutually exclusive.
Firing
Fusing these pieces is, in principle, the same as
encapsulating any organic material within the glass. Slow advances are required with a 3 to 4-hour
soak at around 600°C to burn out any residual organic material just as you
might for thick vegetable matter. You
can add another bubble squeeze soak of an hour or so at around 650°C to
gradually push any remaining air out from between the particles. Then advance to the fusing temperature and
anneal as usual.
